1. Field of the Invention
The present invention relates to a reversible lock core structure for an interchangeable lock core of a door lock mechanism. Particularly, the present invention relates to a rotatable spindle of the door lock mechanism having two longitudinal assembling slots for alternatively combining with an upraised engaging block of an invertable tubular adapter. More particularly, the present invention relates to the rotatable spindle of the door lock mechanism having a pair of retaining notches to receive a positioning protrusion of the invertable tubular adapter.
2. Description of the Related Art
U.S. Pat. No. 5,398,531, entitled “ROTATIONAL HOUSING ASSEMBLY FOR A LOCK ASSEMBLY WITH A REMOVABLE CORE,” discloses a conventional door lock mechanism. The door lock mechanism includes an exterior rotational housing, a spindle and a C-shaped tubular core retainer. The rotational housing is constructed from a handle assembly. The rotational housing has an assembling sleeve which is adapted to receive an interchangeable core and defines an inner periphery. An actuating driver portion is formed on the inner periphery and extended along a longitudinal direction of the inner periphery. The spindle is engaged with the C-shaped tubular core retainer to rotate with the rotational housing. The spindle includes a first end adapted to operate with a door latch assembly, and a second end adapted to cooperate with the rotational housing. A cutout portion is formed in the second end of the spindle and extended along a longitudinal direction of the spindle. The cutout portion has a side edge to provide with a recess. A driver slot is further formed in the second end of the spindle and extended along a longitudinal direction of the spindle. Furthermore, the driver slot is opposite to the cutout portion. The driver slot of the spindle engages with the actuating driver portion of the rotational housing such that the rotational housing retains the spindle in its assembling sleeve. The assembling sleeve of the rotational housing receives the tubular core retainer which is mounted on the second end of the spindle. The tubular core retainer includes a first end and a second end. Formed on the first end of the tubular core retainer is a flange, and formed on the second end of the tubular core retainer is a stop member for engaging with the recess of the cutout portion of the spindle. A cutout is formed on the flange of the tubular core retainer for engaging with the actuating driver portion of rotational housing such that a rotational movement of the tubular core retainer relative to the assembling sleeve of the rotational housing is prevented.
The stop member of the tubular core retainer can prevent a longitudinal movement of the interchangeable lock core relative to the assembling sleeve of the rotational housing when a core catch of the interchangeable lock core is in an extended position. As a result, no removal of the interchangeable lock core from the door lock mechanism occurs. Conversely, the interchangeable lock core is removable if the core catch of the interchangeable lock core is in a retracted position.
A 180-degree turning or reversed turning of this type of the lock core about a longitudinal direction of the spindle cannot be carried out or allowed due to a structural limitation of the spindle itself during installing the door lock mechanism. Consequently, the spindle of the door lock mechanism so configured is unsuitable for installing on a different side or various positions of a particular door plank for installation. This results in a design limitation of the door lock mechanism existing for use in various applications. In addition, the stop member of the tubular core retainer is constructed from an upraised protrusion which can only be suitable for manufacture in a casting or power-metallurgy process. This results in an increase either of the manufacturing cost or the manufacturing difficulty. Hence, there is a need for improving the structures of the spindle and the tubular core retainer of this type of door lock mechanism.
U.S. Pat. No. 6,014,877, entitled “CORE RETAINER FOR A LOCK WITH AN INTERCHANGEABLE LOCK CORE,” discloses another conventional door lock mechanism. The door lock mechanism has an outside handle assembly which includes a spindle, a doorknob and a tubular core retainer. The spindle includes an upper slot and a lower slot, thereby defining a pair of lateral walls. Each lateral wall includes an upper cut portion defined in an upper side thereof and a lower cut portion defined in a lower side thereof. The doorknob mechanically connects with the spindle for actuating a rotational movement of the spindle. The doorknob includes an outside end wall having an 8-shaped assembling opening defined thereon and a projection formed on an inner periphery that defines the 8-shaped assembling opening. The spindle mounts the tubular core retainer which is constructed from a cylindrical main body having a first end provided with a flange formed on an outer periphery thereof, and a second end opposite to the first end. The flange has an outer end face that bears against the outside end wall of the doorknob. A pair of retainer lips is formed on the outer end face of the flange of the tubular core retainer. Formed between the retainer lips is an engaging cut for fittingly engaging with the projection provided in the 8-shaped assembling opening of the doorknob to thereby prevent a rotational movement of the tubular core retainer relative to the doorknob. The tubular core retainer further includes an insert received in one of the upper slot and the lower slot of the spindle. The insert includes a pair of lugs extended beyond the second end of the cylindrical main body. When assembled, each of the lugs of the insert is correspondingly engaged in one of the upper cut portion and the lower cut portion of the spindle that prevents an interchangeable lock core from being pulled outwardly along a longitudinal direction.
In assembling operation, if the insert of the tubular core retainer is received in the upper slot of the spindle, the lugs of the insert are engaged in the upper cut portions of the spindle. Conversely, if the insert of the tubular core retainer is received in the lower slot of the spindle, the lugs of the insert are engaged in the lower cut portions of the spindle. Accordingly, a reversed direction of the interchangeable lock core in relation to the door lock mechanism can be changed.
As explained above, a 180-degree turning or reversed turning of this type of the lock core about a longitudinal direction of the spindle can be carried out according to various types of door handles during installation of the door lock mechanism. The spindle and the tubular core retainer of the door lock mechanism so configured are suitable for installing on a different side or various positions of a particular door plank for installation. However, the insert of the tubular core retainer has a configuration which is suitable for manufacture in a casting or power metallurgy process that may cause an increase in manufacturing cost and manufacturing difficulty. Hence, there is a need for improving the structures of the spindle and the tubular core retainer of this type of door lock mechanism.
The present invention intends to provide a rotatable spindle of the door lock mechanism having a first longitudinal assembling slot and a second longitudinal assembling slot for alternatively combining with an upraised engaging block of an invertable tubular adapter. The upraised engaging block of the invertable tubular adapter can be manufactured in a punching process. Advantageously, the invertable tubular adapter so configured can reduce manufacturing cost and eliminate manufacturing difficulties in such a way as to mitigate and overcome the above problem. Furthermore, the invertable tubular adapter includes at least one positioning protrusion to be positioned in one of the retaining notches of the rotatable spindle to prevent any radial movement of the invertable tubular adapter in the rotatable spindle. Accordingly, this ensures an increase of reliability of the assembled relationship of the rotatable spindle and the invertable tubular adapter of the door lock mechanism.